The Old School Emulation Center (TOSEC) is a retrocomputing initiative dedicated to the cataloging and preservation of software, firmware and resources for microcomputers, minicomputers and video game consoles. The main goal of the project is to catalog and audit all possible kinds of software and firmware images for these systems. To support this, the TOSEC Naming Convention (TNC) was created. The TNC is the set of standardized rules used by TOSEC renamers to provide a consistent, clear and concise naming scheme for cataloging any image from any system. This document serves to cover and describe the entire naming convention and how it should be used.